diff --git a/designer-base/src/main/java/com/fr/design/gui/icontainer/UIModeControlContainer.java b/designer-base/src/main/java/com/fr/design/gui/icontainer/UIModeControlContainer.java
index a589b0c878..73bfa0ef79 100644
--- a/designer-base/src/main/java/com/fr/design/gui/icontainer/UIModeControlContainer.java
+++ b/designer-base/src/main/java/com/fr/design/gui/icontainer/UIModeControlContainer.java
@@ -166,6 +166,9 @@ public class UIModeControlContainer extends JLayeredPane {
             }
             // 拖动的距离，为正值表示往下拖动，为负值表示往上拖动
             int deltaY = e.getY();
+            if (toolPaneY < 0) {
+                toolPaneY = 0;
+            }
             toolPaneY += deltaY;
             onResize(toolPaneY);
             refreshContainer();